This invention relates broadly to the art of medical lavage devices and particularly to those which can be used for quickly exchanging fluids of body cavities.
This invention can be used with medical lavage apparatus of the type disclosed in U.S. Pat. Nos. 4,872,866 and 4,842,581 to Davis.
U.S. Pat. Nos. 4,872,866 and 4,842,581 to Davis describe medical lavage apparatus comprising parallel irrigation and aspiration cylinders communicating with a common exchange tube. The irrigation cylinder includes an inlet port and the aspiration cylinder includes an outlet port through which fluid from a supply container is pumped into and out of the body cavity as irrigation and aspiration plungers are moved in their respective cylinders. These patents disclose an anti-venturi septum and various valves which channel fluid flow from a supply container into the body cavity and out of the body cavity through the outlet port to a waste container. These patents also disclose loop handles having adjacent, relatively-straight, parallel, sides positioned close to each other to allow a user to grip and operate both the irrigation and aspiration plungers at the same time as well as individually.
Although the medical lavage syringe device of these patents has proven to be quite beneficial, several improvements would be helpful to improve its performance over a wider range of operation. Under normal circumstances, where an evacuation fluid is moderately clean, simultaneous operation of the irrigation and aspiration plungers directs evacuation fluid as described above. However, should the exchange tube, or a tube attached to the exchange tube extending into the cavity to be evacuated, become clogged with debris, simultaneous operation of the plungers can cause fluid to travel directly from the inlet port of the irrigation cylinder to the outlet port of the aspiration cylinder without going into the cavity to be evacuated. Thus, it is an object of this invention, to provide a medical lavage syringe having irrigation aspiration plungers which can be operated in a foolproof manner to assure that irrigation fluid passes through a cavity to be evacuated.
A feature of the medical lavage syringe device of U.S. Pat. Nos. 4,872,866 and 4,842,581 to Davis is that when the aspiration plunger thereof is fully inserted in its aspiration cylinder its seal covers the outlet port so that the irrigation plunger can be operated to pump fluid from the supply container into the cavity to be evacuated without fear of this fluid passing directly to the outlet port. However, when one fully seats the aspiration plunger and then operates the irrigation plunger against a debris-filled exchange tube, fluid pressure tends to move the aspiration plunger away from the fully seated position, thereby again uncovering the outlet port and allowing fluid to by-pass directly from the inlet port to the outlet port without going into the cavity to be irrigated. It is therefore an object of this invention, to provide a medical lavage syringe device of the type described in which an irrigation plunger thereof can be independently operated with assurance that fresh evacuation fluid is pumped into a cavity to be evacuated.
The loop handles of the above described patents can only be gripped in a manner intended for operating both the irrigation and the aspiration plungers simultaneously when they are aligned with one another. However, it has been found, that the plungers tend to rotate easily in their respective cylinders so that when the plungers are operated individually, the handles tend to come out of alignment. Thus, it is another object of this invention, to provide a medical lavage syringe device of the type described in which plungers, and handles therefor, remain in a fixed rotational orientation while they are being driven.
Yet another difficulty with the medical lavage syringe device described in the above cited patents is that when the plungers thereof are being operated, they can be easily inadvertently pulled from their respective cylinders, and/or driven from their respective cylinders by fluid pressure. If the plungers come out of the cylinders, this can contaminate clean areas and can be quite messy. Further, it can be time consuming and quite awkward for an operator to have to reinsert the plungers. Thus, it is another object of this invention to provide a medical lavage syringe device, of the type described, in which the plungers are not allowed to inadvertently leave their respective cylinders.